Neutral I rate the quality of workmanship and the flare-behavior.
The lens has a metal bayonet and is otherwise made of well manufactured plastic. Here creaks and wobbles nothing! The slight rubber coating on the zoom and the focus ring a good impression after three months of use. Only the lens hood is sometimes quite difficult to move when placed and gives you the feeling to have it recognized or canted wrong.
Similarly, when side light is (maybe because I alone for protection reasons Scan almost always with attached lens hood) basically very unobtrusive and the contrasts are always good! Only when sunlight falls directly onto the lens, there are sometimes extremely ugly and shapeless green Lensflares, which can not be always easy to remove in post.
Chromatic aberrations also keep in check and are in post-production (I use Lightroom) anyway away with one click. Therefore bother me the color fringes anyway rarely occurring not particularly.
Really negative I noticed so far to the Sigma lens anything yet. Only the focus ring acts during the manual focus a little cheap, because it is not attenuated. A manual intervention in the auto focus is not possible. But at least he is quite fast and relatively quiet.
Otherwise, I enjoy this lens especially the high flexibility when traveling and want to take only one lens. One can easily in a moment make a tack-sharp uptake in the city and in the next moment one uses the Image Stabilizer and high luminous intensity from to make in an underpass a shake-recording in extremely low light. But also for portraits, the lens on my APS-C camera is ideal. Whether it be. In studio-like setting, outdoors or in bad light in the ballroom of a wedding party
As a final treat, I would like to mention the good close focus range. The 0,28m stated are measured from the sensor to. That means I can go ran at 50mm up to 9cm to the lens, which allows quite good detail shots.
I would recommend the Sigma 17-50mm 2.8 on any event to anyone who wants a bright standard zoom lens for under 400.
